Motor stop-start arrangement for telegraph receivers



Jan. 17, 1950 1'. G. FI'OULTER MOTOR STOP-START ARRANGEMENT FOR TELEGRAPH RECEIVERS Filed July a, 1948 TIME DELAY) RELAY TIME DELAY RELAY r0 RECEI/AIG r'o MOTO 10 657' SUPPLY IDRECE/W/VE SET --se in the electric control,

and open when it is on mark. the said first control a limiting resistance across a battery or other rela Patented Jan. 17, 1953 .iMGTQ-ItrSFIfiP-S'DART AIt-RANGEMENTZFQR TELEGRAPH BJEGEI'V -ERS Thomas "Geoffrey *Poulter; "Chelmsiord, -England,

"assignor to *lVIa-rconis Wireless Telegraph-Company-Lim'ited, London, England, a-company of Grcat Britain Application-July f8, 194$,.Serial'No.37,;643

'InGrQatBritain Julyj31, 1 94 iroiaims. (Cline-4.1:

This invention relates to motor stop-start-arrangements for printing telegraph and like receivers and more particularly to 'such arrangements of the kind :in whichthe usual printing telegraph receiver motor is provided with a control circuit whereby it may he stopped or started by suitable telegraph signals transmitted from the co-operating transmitter.

The invention is illustrated in and explained in connection with the accompanying drawings in which Fig. l is a diagrammatic figure, provided for explanatory purposes, illustrating a known arrangement, and Fig. 2*is a diagrammatic figure illustrating an embodiment of the present invention.

order that the invention may be the better understood a known motor stop-start arrange-. ment of the kind reierred to will first be described together with the vent-ion seeks to avoid. In this known arrangedefects which the present inment, illustrated in Fig. '1, the armature 2 of the printing telegraph receiver relay, whose winding l is connected to the receiving set (not shown) is provided with back contacts 3 in parallel with the winding-'4 of a first-control relay whose armature has an end slug which delays its operation, on energization, by about .50 milli-seconds :and its release, on de-energization, by about 10.0 :milliseconds. Such sl-ugged relays are well-known rper telegraph and automatic telephone arts and are therefore deemed to require no detailed description herein. One.:eX- ample of such relay is illustrated for example in C. P. Clare Patent 2,355,055, datedAug st 8, .1944.

The saidhack contacts are normally closed, i. e.'

telegraph relayis on space The winding 4 of relay is connected through are .closed when the source (not shown but represented byits positive and negative terminals and and when energized, closes (after the delay stated) normally open contacts 6 which are in series with the closing coil la of a two-coil relay. This series circuit, which extends irom the battery or other source, also includes the normally closed contacts l? of a iii-metallic thermal or other delay relay as well known per se the heating winding 1 I of which is also connected to the source through the normally open contacts 6 of the first control when energized, The two-coil relay has two pairs 8, 19. of normally open contacts one pair '9 of which, when closed completes the circuit of the motor ill and the other pair '8 of which, when closed connects the second or locking coil lb of 2 the relay in question to the said source, this circuit also including the thermal relay contacts I2.

With this arrangement a prolonged mark sig- 'na-lofaloout /2 to isecond starts the motor ill by closing the contacts ii of the first control relay W-hichin turn energizes thetwo-coil relay (which looks itself in) to complete the motor circuit. A

longer mark offabout 1'0 seconds duration stops the motor by first causing energization of the first control relay and then causing the thermal relayto open its-contacts l2 and thus break the circuits of both windings la, "lb of the two-coil 'to'operate the thermal relay,

relay.

This circuit has two main disadvantages. If

the transmitter opera'tor sends a stop signal appreciably longer than the ten seconds necessary the bi-metallic element or" this relay-becomes much overheated and "takes about 2 minutes to restore instead of the usual to seconds. it is not possible to restart the motor by the start the-stop signal.

f-trol relay is not immune especially in aperiod when no message is being 'tacts l2 and thus stop the motor.

Until this relay restores signa-L w-hich often comes about /2 minute after Secondly the slugged first confrom operation by noise,

sent. If the said relay operates on noise the motor starts and blank tape is fed from the telegraph receiver. Further the said rela is apt to operate manual stop-start switch. For these reasons the known system described is not reliable enough to he left without supervision. The present invention seeks to avoid these-defects.

According to this invention a printing tele- "graph or like "receiver motor start-stop arrangement of the kind referred to comprises a first control relay whosewinding is connected in circuit so as to be energized when the normally provided telegraph receiver'ison space, delay means associated with said relay to delay its release after said circuit is broken, a motor control relay having an operating winding connected to be ener gized on release of said first control relay and adapted on energization, to complete the motor circuit, a maintaining circuit adapted to he closed on energization of said operating winding and to maintain the motor circuit completed after said operating w-indinghas been-energized, and a ther- Since the In a preferred embodiment illustrated in Fi 2 the winding 2| of the normally provided telegraph relay operates by its armature 22 back contacts 23 which, when the relay is on space, energizes the winding 24 of a first control relay ing telegraph receiver motor is provided with a control circuit which stops and starts said motor under the control of telegraph signals transmitted thereto from a co-operating transmitter, the combination of a first control relay having a winding, means connecting said winding in circuit so as to energize the same when the normally provided telegraph receiver is on space, delay means associated with said relay to delay its release after said circuit is broken, a motor control relay having an operating winding, means connecting said operating winding to energize the same on release of said first control relay,

having a pair of normally closed contacts 26 This winding has a condenser l3 in parallel therewith whereby, open, the charge on of the first control relay by about 250 milliseconds. The normally closed contacts 26 com-i plete the energizing circuit of one winding 21a of a two-coil relay, said circuit also including, in series, the normally closed contacts N2 of a thermal or other delay relay of any convenient well known construction having a delay of about to 7 seconds. The two-coil relay has a second, or maintaining, winding 27b the circuit of which is completed by contacts 28 which the said relay itself closes when actuated, said relay also having normally open contacts 29 which, when closed, complete the The heater winding 2 of the thermal relay is in series with both the normally closed contacts 26 of the first control relay and with the contacts 2l2 of the said thermal relay itself, the last mentioned contacts also being in the circuits of both coils 27a, 21b of the two-coil relay.

With this arrangement the transmission of a mark of substantially more than 250 milliseconds duration causes release of the first control relay, operation and locking-in of the two-coil relay and starting of the motor. Thereafter transmission of a mark exceeding the thermal relay delay e. g. a mark of seconds-causes the thermal relay to open its contacts 2l2 tripping out the two-coil relay and stopping the motor. heater circuit is broken immediately the thermal relay contacts open, the heater begins to cool immediately, however long the mark to stop the motor may be. After a further seconds the thermal relay contacts 2|2, which have a toggle action, in the ordinary well known way return to their original position and the arrangement is ready for another start signal.

The main advantages of the above described circuit are:

(:1) Since noise cannot cause the motor to start, the receiver will not feed out tape during idle periods.

(b) Since normal signals do not operate the control circuit, the receiver will not stop during reception of traflic.

(c) The receiver is always ready to receive a start signal within about 20 seconds of the end of a stop signal irrespective of the length of the stop signal.

circuit of the motor 3.,-

when the back contacts 23 the condenser delays release I means, actuated on energization of said operating winding, for completing the motor circuit, a maintaining circuit connected to be closed on energization of said operating winding for maintaining the motor circuit completed after said (d) Because of its immunity from operation by noise, the apparatus may be used on any circuit which is good enough to give legible printing, whether by line or by wireless.

It is found that the improved reliability is I such that an apparatus as above described can be safely left unattendeda great advantage.

What I claim is: 1. In a printing telegraph or like receiver motor stop-start arrangement wherein the printcircuit which stops operating winding has been energized, and a delay relay having a winding connected to be energized on energization of the first control relay and having contacts connected to break said maintaining circuit and also the circuits of said last mentioned winding and of said operating winding on operation of said delay relay.

2. In a printing telegraph or like receiver motor stop-start arrangement wherein the printing telegraph receiver motor is provided with a control circuit which stops and starts said motor under the control of telegraph signals transmitted thereto from a oo-operating transmitter, the combination of a first control relay having a winding, means connecting said winding in circuit so as to energize the same when the normally provided telegraph receiver is on space, delay means associated with said relay to delay its release after said circuit is broken, a motor control relay having an operatin winding, means connecting said operating winding to energize the same on release of said first control relay, means, actuated on energization of said operating winding, for completing the motor circuit, a maintaining circuit connected to be closed on energization of said operating winding for maintaining the motor circuit completed after said operating winding has been energized, and a thermal delay relay having a winding connected to be energized on energization of the first control relay and having contacts connected to break said maintaining circuit and also the circuits of said last mentioned winding and said operating winding on operation of said delay relay.

3. In a printing telegraph or like receiver motor stop-start arrangement wherein the printing telegraph receiver motor is provided with a control and starts said motor under the control of telegraph signals transmitted thereto from a co-operating transmitter, the combination of a first control relay having a winding, means connecting said winding in circuit so as to energize the same when the normally provided telegraph receiver is on space, delay means comprising a condenser in parallel with the winding said relay to delay its release after said circuit is broken, a motor control relay having an operating winding, means connecting said operating winding to energize the same on release of said first control relay, means actuated on energization of said operating winding, for completing the motor circuit, a maintaining circuit connected to be closed on energization of said operating winding for maintaining the motor circuit completed after said operating Winding has been energized, and a delay relay having a winding connected to be energized on energization of the first control relay and having contacts connected to break said maintaining circuit and also the circuits of said last mentioned winding of said operating winding on operation of said delay relay.

4. In a printing telegraph or like receiver motor stop-start arrangement wherein the printing telegraph receiver motor is provided with a control circuit which stops and starts said motor under the control of telegraph signals transmitted thereto from a co-operating transmitter, the combination of a first control relay having a winding, means connecting said winding in circuit so as to energize the same when the normally provided telegraph receiver is on space, delay means comprising a condenser in parallel with the windil'lg said relay to delay its release after said circuit is broken, a motor control relay having an operating winding, means connecting said operating winding to energize the same on release of said first control relay, means, actuated on energization of said operating winding, for completing the motor circuit, a maintaining circuit 6 connected to be closed on energization of said operating winding for maintaining the motor circuit completed after said operating winding has been energized, and a thermal delay relay having a winding connected to be energized on energization of the first control relay and having contacts connected to break said maintaining circuit and also the circuits of said last mentioned winding and said operating winding on operation of said delay relay.

THOMAS GEOFFREY POULTER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

